Field of the Disclosure
The present disclosure relates generally to balloon assemblies having controllable topographies and systems and methods relating to the same.
Discussion of the Related Art
Balloons intended for use within a mammalian body, such as a human, are employed in a variety of medical procedures, including dilation of narrowed blood vessels, placement of stents and other implantable devices, temporary or permanent occlusion of blood vessels, drug delivery, thrombectomy, embolectomy, atherectomy, angioplasty, other endovascular procedures, and other procedures within a lumen of a mammalian body such as a human body. In this regard, as used herein, the term “body” can comprise a mammalian body such as a human body or other animal body.
In a typical application, a balloon (often coupled with a catheter) is advanced to the desired location in the vascular system or other lumen of the body. The balloon is then pressure-expanded in accordance with a medical procedure. Thereafter, the pressure is removed from the balloon, allowing the balloon to contract and permit removal of the catheter and, in many cases, the balloon.
Procedures such as these are generally considered minimally invasive, and are often performed in a manner which minimizes disruption to the patient's body. As a result, balloons are often inserted from a location remote from the region to be treated. For example, during angioplasty procedures involving coronary vessels, the balloon catheter is typically inserted into the femoral artery in the groin region of the patient, and then advanced through vessels into the coronary region of the patient. These balloons typically include some type of radiopaque marker to allow the physician performing the procedure to monitor the progress of the catheter through the body.
Non-compliant balloons are generally made of relatively strong but generally inelastic material (e.g., nylon, polyester, etc.), which must be folded to obtain a compact, small diameter cross section for delivery. These relatively stiff balloons do not easily conform to the surrounding vessel and thus can be used to compact hard deposits in vessels. Due to the need for strength and stiffness, these devices are rated to employ high inflation pressures, usually up to about 4 to about 60 atmospheres. As depicted in FIG. 1, non-compliant balloons (line C) have a maximum diameter, and as inflation fluid is introduced, such balloons will not normally distend appreciably beyond a maximum diameter. Once a non-compliant balloon is inflated to its maximum diameter, the exertion of additional pressure can cause rupture of the balloon, creating a hazardous condition.
By contrast, compliant balloons generally comprise soft, elastic material (e.g., natural rubber latex). As depicted in FIG. 1, compliant balloons (line A) will generally expand continuously in diameter and will not appreciably increase in internal pressure as inflation fluid is introduced. As a result, compliant balloons are generally rated by volume (e.g., 0.3 cc) rather than by nominal diameter. Also, compliant balloons generally conform to the shape of the vessel. Although comparatively weak compared to non-compliant balloons, compliant balloons have the advantage that they need not be folded about a delivery catheter (reducing profile) and tend to readily recompact to their initial size and dimensions following inflation and subsequent deflation. These balloons can be employed to displace soft deposits, such as a thrombus, where a soft and tacky material such as latex provides an effective extraction means, and also can be used as an occlusion balloon, operating at low pressures.
In between the spectrum of compliant balloons and non-compliant balloons fall semi-compliant balloons. As depicted in FIG. 1, semi-compliant balloons (line B) will both increase in pressure and increase in diameter as inflation fluid is introduced. However, semi-compliant balloons operate at pressures in between the two types of balloons and will continue to distend as inflation fluid is introduced.
Both compliant and non-compliant balloons tend to have a uniform surface topography. In other words, conventional balloons tend to have smooth surfaces. Balloons with more varied topographies may facilitate a variety of medical procedures and therapies not possible using conventional balloons. For instance, a variable topography may provide increased surface area over a similar conventional balloon, and thus interaction with the body may be improved. A variable topography balloon may also be configured to deploy sharp objects in a localized, difficult to reach part of the body, providing an improvement in therapy. In addition, variable topography balloons may provide improved drug delivery systems. Moreover, it would be beneficial for a balloon to have a controllable topography.